SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cf580dd4ea54b1d484f5f39954954df97eb546bbeb8647f2e607faa30ded9446' 
  AND token = 'agE9TUKmXvcezdL5+G0YcYVxtoNBZM2x8P5BSquPdhE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}