SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '444b0f1580ca550381fbd2546e6056391dedbfbd2a48e1127dc2cec527b98444' 
  AND token = 'awPIQneXPQzFN4qYXrnvhuhQJ1q/Fw9YmzzZevJX3/U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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