SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'debd15472e9d1a0a31fa4a6d819e32fdeff502ca9ba854a133f17fb79d321bc8' 
  AND token = 'W+GN3s2t/EP7rMgvZjJP7HZJFQabF6Bjlhz7HzhKF3Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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