SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '48113c6a91398d6592d325238c5ae2cfba0ecdcf52828e2c1c2706b4300d9ceb' 
  AND token = 'NkDrEeOKfD+T24kImnSHE3cIZahbyfqCR0arL3QlsGQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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