SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7c767295d12781bc421b58b2c97e840f870d6de06d5db1706fac216faea89d43' 
  AND token = 'ZNVlBPMmGEOZ13Xd+jLdsoRbnm840kHayPZZcsZDsA8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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