SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cf8b46bc7dead8aac6b451165dbe539e6e0c99db82c606516fc3536a31779a0f' 
  AND token = 'vQEYJUuNx4uDLompuABJgVsWwae/FMxAWdeKH5n0BJk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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