SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7af7d8cc51493d72294567d1dd455d53aeffe9242eba7385564efd17103b6f82' 
  AND token = 'OTJENkeiBnOLTdwhVO/jdDozHKT+AJldzKSyYSzqcPE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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