SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a0fdcba88af4ce5a36630afa9484ddbe4d02819a1ff6479b6ecc1c8c96b705e9' 
  AND token = 'RbK9qHTGBX2a9bnCgtGOK7HUS+FPEFwnUeY8RT6Or5I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00044

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}