SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c5519bc81e2baea3cf24bd57e02b69824c118a940c4777a6b4aeb5d632f105e0' 
  AND token = 'PU1CJYPVZX1675Cjbn+K4k2a+fjlriBr/npglzkgUgQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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