SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '38d1260e920edcbdaf246abafc1c6bf480ff3f30ee545f427885d81b0b1d1db8' 
  AND token = 'OAARnNIUS1u0bKViRbcktVIgdSByRhmYcdA7CtF+SNg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

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