SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '03e78f16408dcd2258fa4ff19f7385ed34b83706ae42049b3745e5383a1b85d4' 
  AND token = '24Img5trA9pyW1UJ/hfo6FuBjPWxVFQRsXcywpzq16c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00058

JSON explain

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