SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '224a29a99fcb4fe4226615a100c465088febb81871d6872cf1008b15420373b9' 
  AND token = 'tQbQldFX2lJhtgdTDSLHB3mWSdr/W2kPTuN5XWmHaHY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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