SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '27a301e151872e4c76538d7bd4ac844d4cf4e8bcfee1ccaa35e581d73b2042be' 
  AND token = 'IQCnLYYkpks2bx/P8gy9M/N5vBiVyE2SXJWFTJie/vo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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