SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '456ca5e470aa4f482c2421e2e795e4b2791533f5736e8cba20c9d07a1b7da8ab' 
  AND token = 'diz5/EIPY0e7Dn398jlp67epse5fmOOD3Ve6Ak4ELkI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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