SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2fd98b611e2809cf10e445cafd1667d0774deaaa55b00eb71bb5da06d1ef0ac4' 
  AND token = 'aDdtZZ+TEjorxbRaRIGy88IclWh1pbUZe1Zp7m49/TQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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