SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'afb2d3a61e0660859c4ad67439476491d39d5611917fda00fd32aeae072ddd43' 
  AND token = 'g+BH5JQQohULOwCauPZjpfJG83WBxn85JuqXXnC5ZZc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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