SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b0ece6a0a2ba9666423a50544406a217a5ff4ffa1609d22432780d309537510c' 
  AND token = '27d2xf+MQCwYv0g+TAByTyxrSIVCHr0gpW86ZgzaAcs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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