SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dc84802557da9fc3ee8aea82a40ebba0a65fcb90ef1ce3c221edf8233115d870' 
  AND token = 'O54uMfXBpnICKyuNBBFd6lgK/M1ueu/tUBsJIY/pcIA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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