SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f3c031a905cd08429644d66b09617e695c158dbd286818430049da0687c9f2ca' 
  AND token = 'ts9DJT6JlyqlN7wZKM7prnVFTWc/DrIakzWFzqe18K8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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