SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'da46202acd3886737593778f8c524b12be102fd75219cc73bcd3270fb3020671' 
  AND token = 's63Pd7lVSRACJccWwBMotEigfy5gFc1nwhxXymEUAqg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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